Firebase functions/firestore not working and catch returning an empty object

Question

I would just like to access my Firestore Database from within my Firebase Functions. I have tried to follow all the documentation and other stack overflow questions but still it is not working. Here is my code:

const functions = require('firebase-functions');
const admin = require('firebase-admin');
admin.initializeApp(functions.config().firebase);

exports.test = functions.https.onRequest((request, response) => {
  admin
    .firestore()
    .collection('users')
    .get()
    .then(querySnapshot => {
      const arrUsers = querySnapshot.map(element => element.data());
      return response.send(arrUsers);
    }).catch((error) => {
      // It is coming in here, and this below just returns '{}'
      response.send(error);
    });
});

What am I doing wrong?

Renaud Tarnec · Accepted Answer · 2019-12-19 21:45:04Z

4

The get() method of a CollectionReference returns a QuerySnapshot which "contains zero or more DocumentSnapshot objects representing the results of a query. The documents can be accessed as an array via the docs property or enumerated using the forEach() method".

Therefore you should do as follows, calling map() on querySnapshot.docs:

exports.test = functions.https.onRequest((request, response) => {
  admin
    .firestore()
    .collection('users')
    .get()
    .then(querySnapshot => {
      const arrUsers = querySnapshot.docs.map(element => element.data());
      //return response.send(arrUsers);  //You don't need to use return for an HTTPS Cloud Function
      response.send(arrUsers);   //Just use response.send()
    }).catch(error => {
      //response.send(error);
      response.status(500).send(error)   //use status(500) here
    });
});

Note the changes to the code for returning the response and handling the error. I would suggest that you watch this official Firebase video on HTTPS Cloud Functions: https://www.youtube.com/watch?v=7IkUgCLr5oA, it's a must!

edited Dec 19, 2019 at 21:45

answered Dec 19, 2019 at 21:02

Renaud Tarnec

83.4k10 gold badges99 silver badges130 bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

ExcessJudgment Over a year ago

I highly recommend this documentation when working with cloud functions. Great examples: googleapis.dev/nodejs/firestore/latest/index.html

Frank van Puffelen Over a year ago

Good answer! On querySnapshot.docs.map(... I keep making this mistake myself, since QuerySnapshot does implement forEach(), but does not implement map().

Frank Over a year ago

Thank you very much! I think the important thing I missed was the querySnapshot.DOCS part. Also thank you for the extra links to learn some more! Stuff like this is always useful

Collectives™ on Stack Overflow

Firebase functions/firestore not working and catch returning an empty object

1 Answer 1

3 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

3 Comments

Your Answer

Sign up or log in

Post as a guest

Related